The invention relates to a method for making families of steady-state heat transfer coefficient curves visible by photochemical means, by applying a moist photogelatin layer to a surface subjected to a gas stream.
One proposed method for displaying families of heat transfer coefficient curves is the so-called "isohumid method" described in our commonly-assigned, co-pending patent application, Ser. No. 132,769, filed Mar. 24, 1980 now U.S. Pat. No. 4,259,431. This method uses a purely photographic development for making the isohumids visible. Families of steady-state heat transfer coefficient curves are made visible by pressing exposed wet films on unexposed films in a dark room, seeding the wet copy with hydrogen sulfide gas and developing it into a transparent silver image with commercially available photographic developers. This method requires a dark room and hydrogen sulfide is used for generating developable image seeds in the photographic layer of the wet film. Disadvantages of hydrogen sulfide are particularly its high toxicity and objectionable odor. An exhaust system is necessary when this compound is used.